Non-volatile memory express, also known as NVMe or NVM Express, is a specification that allows a solid-state drive (SSD) to make effective use of a high-speed Peripheral Component Interconnect Express (PCIe) bus attached to a computing device or host. Here the PCIe bus is a high-speed serial computer expansion bus designed to support hardware I/O virtualization and to enable maximum system bus throughput, low I/O pin count and small physical footprint for bus devices. NVMe typically operates on a non-volatile memory controller of the host, which manages the data stored on the non-volatile memory (e.g., SSD) and communicates with the host. Such an NVMe controller provides a command set and feature set for PCIe-based SSD access with the goals of increased and efficient performance and interoperability on a broad range of enterprise and client systems. The main benefits of using an NVMe controller to access PCIe-based SSDs are reduced latency, increased Input/Output (I/O) operations per second (IOPS) and lower power consumption, in comparison to Serial Attached SCSI (SAS)-based or Serial ATA (SATA)-based SSDs through the streamlining of the I/O stack.
Service providers have been increasingly providing their web services (e.g., web sites) at third party data centers in the cloud by running a plurality of virtual machines (VMs) on a host/server at the data center. Here, a VM is a software implementation of a physical machine (i.e. a computer) that executes programs to emulate an existing computing environment such as an operating system (OS). The VM runs on top of a hypervisor, which creates and runs one or more VMs on the host. The hypervisor presents each VM with a virtual operating platform and manages the execution of each VM on the host. By enabling multiple VMs having different operating systems to share the same host machine, the hypervisor leads to more efficient use of computing resources, both in terms of energy consumption and cost effectiveness, especially in a cloud computing environment.
Currently, the host of the VMs only sees a single instance of the physically connected NVMe controller and only the hypervisor running on the host can have access to the physical NVMe controller. Consequently, all of the VMs running on the host have to share the same NVMe controller and have to go through the hypervisor to access the storage units (namespaces) associated with the NVMe controller. Since the VMs running on the host at the data center may belong to different web service providers, it would be desirable for each of the VMs to have its own dedicated NVMe controller and namespace for its own storage units instead of sharing with other VMs.
The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent upon a reading of the specification and a study of the drawings.